Cartridge powered fastener driver



April 26, 1966 H. 1.. BOCHMAN, JR 3,248,032

CARTRIDGE POWERED FASTENER DRIVER 2 Sheets-Sheet 1 Filed Jan. 6, 1964April 26, 1966 H. L. BOCHMAN, JR

CARTRIDGE POWERED FASTENER DRIVER 2 Sheets-Sheet 2 Filed Jan. 6, 1964HARE Y l. BOCHMAN, JR

ATTORNEYS.

United States Patent 3,248,532 CARTREDGE POWERED FASTENER DRIVER HarryL. Bcchman, J12, Seal Beach, Calif., assignor to Hi-Shear Corporation,Torrance, Calif., a corporation of California Filed Jan. 6, 1964, Ser.No. 335,933 2 Qlaims. (Cl. 2278) This invention relates to poweractuated drivers for driving elongated objects such as nails.

It is an object of this invention to provide a gun to drive nails whichgun has a variable power control, even when the source of energy is at aconstant level, whereby the operator may vary the driving force on thenail in accordance with the needs of an individual job.

A related object of the invention is to provide a means to shield theoperator of the device from detritus which may be scattered by impact ofthe nail with the material into which it is driven.

Another related object is to provide a means to lock the device so thata nail cannot be driven when the safety shield is removed, nor when thedischarge end of the device is not forced against the material to befastened.

Frequently in the use of power drivers for fasteners, such as a driverto drive nails to attach two pieces of material together, the driver hasa force unsuitable for the material being fastened. If the nail is to bedriven through plasterboard, a relatively light force is desirable,while a relatively large force is needed to drive the nail intohardwood. The force on the nail may be too great tending to damage thematerial, or the force may be so small on the nail that it will notenter into the material. Also, when the driver is driven bytrigger-actuated means, it is necessary to be sure that the nail cannotbe shot freely through the air but only into an intended surface whichis to receive and stop.

A nail driver in accordance with this invention is a gun adapted toaccept an explosive charge which when detonated will fire a nail into apiece of material. By providing an adjustable expansion chamber, tappedoff the bore through which the nail is fired, the energy of the fastenermay be adjusted.

According to a preferred but optional feature of this invention, acup-like guard is placed over the discharge end of the barrel to shieldthe operator from any flying detritus. To fire the gun the discharge endof the device must bear against the material to be fastened withsufficient force to move the spring-loaded barrel towards the handle ofthe gun. Only when the barrel is in such a position may the gun becooked and the trigger caused to actuate the firing pin and explode thecharge.

The above and other features of this invention will be more completelyunderstood in the following detailed description and accompanyingdrawings of which:

FIG. 1 is a front view in cross-section of a power actuated driver inaccordance with this invention;

FIG. 2 is a top view of part of the device shown in FIG. 1 partially incross-section;

FIG. 3 is a cross-section view of the device taken at line 33 of FIG. 1;

FIG. 4 is a cross-section view of the device taken at line 4-4 of FIG.1;

FIG. 5 is a cross-section view of the device taken at line 5-5 of FIG.1;

FIG. 6 is a cross-section view of the device taken at line 66 of FIG. 1;

FIG. 7 is a side view of the trigger mechanism when the device is in acocked position;

FIG. 8 is a cross-section view of the device taken at line 3-8 of FIG.1; and

FIG. 9 is a view taken at line 99 of FIG. 1.

The drawings show a gun 10 operable to detonate an explosive charge 11in order to drive a nail 12 into a surface. The driver comprises abarrel 13 which has a circular bore 14 centrally disposed and of thesame diameter as the size of the nail head 12a along a longitudinal axis15. Barrel 13 is eccentrically enveloped within a front case 16 and arear case 17 as shown in FIGS. 1 and 3. Front case 16 and rear case =17are substantially eliptical in cross-section and join together at joint18. A handle is attached to the rear case 17 such as by welding at theend opposite joint 18 and the barrel is slidalbly engaged within thefront and rear case to move relative to the handle. Handle 19 has an endplate 20 attached by a screw 21 shown in FIG. 2 on .the side facing thebarrel '1-1. The handle has a hand grip 22 with a trigger 23 attachedthereon with a trigger guard 24 connected between the hand grip 22 andrear case 17. A circular shaft 25 is attached to the trigger 23 and isslidable with-in a bore hole 26 in the handle 19 along an axis parallelto longitudinal axis 15 at a position directly above hand grip 22. Shaft25 has a cavity 26a shown in 'FIG. 7 adapted to accept a compressionspring 27 disposed in bore hole 26. Spring 27 tends to force trigger 23away from hand grip 22 in the conventional manner. Trigger 23 isslidable in a longitudinal slot 28 in the end of rear case 17.

A spring chamber 39 is centrally disposed parallel to axis 15. It isshown in FIG. 2 in the handle and houses a firing pin power spring 32 incompression operable to actuate a firing pin 33. Longitudinal axis 31 isparallel to and spaced from axis 15in a horizontal plane .as shown inFIGS. 1 and 2. Pin 33 has a retaining sleeve 33a fixed to thenon-detonating end and disposed to slide within chamber 30. Spring 32bears against sleeve 33a on pin 33 biasing the pin to move through endplate 20. End plate 20 has a circular hole 20a centrally located on axis31 having a size which allows pin 33 to pass therethrough but whichrestricts sleeve 33a. FIG. 7 shows trigger 23 to have an upwardlyextending arm 34 adapted to strike a pawl 35 which is pivoted about apin 36. Pawl 35 is an elbow shaped member having .an arm 37spring-loaded by compression spring 38 to bear against arm 34 of trigger23. Pawl 35 has a second arm 39 which is operable to rotate a searmechanism 40 to release firing pin 33.

1 attached at the end pawl 35. Shaft 51 is biased to rotate in acounterclockwise direction as shown in FIG. 7 by a spring 52 shown inFIG. 2. Firing pin 33 has a rearward section 331; of larger diameterthan its forward section. Section 33b bears against shaft 5 1 when thepin is cooked and the device is ready to fire.

FIG. 2 shows Wheel 50 ofiset from longitudinal axis 31 and spaced fromarm .39 of pawl 35. Block 47 is slidable in rear case 17 to a positionwierein pad 48 abuts plate 20 so that arm 39 of pawl 35 will strike aprotruding lug 53 on wheel 50 when pawl 35 is rotated about pivot pin 36by trigger23. The positioning of lug 53 and arm 39 is described in theoperation of the device. Wheel 50 has a restraining lu-g 54 operable toabut against a restraining pin attached to block 47 to stop, shaft 5 1from unwinding the tension of spring 52. Shaft 51 has 3 a flat land 55which, upon rotation of shaft 51, will release the large diameter rearsection 33b of spring biased firing pin 33 to allow it to move alongaxis 31' toward a firing chamber 56 located at the breech end 44 ofbarrel 13. Firing chamber 56 is concentrically located on the end ofbore 14 and has a circular hole extending stantially elliptical in.cross-section as shown in FIG.-4

and barrel 13 is eccentrically disposed therein. An' expansion chamber62 is aligned parallel to longitudinal axis in block 60 opposite barrel13. A pivot shaft 63 attached to a piston 64 in the expansion chamberextends parallel to axis 15 through the block 47 and into a circularhole 65 extending through handle 19. Shaft 63 has external threads 66adapted to thread into internal threads cut into a central hole 67 inpiston 64. A pressure sealing sleeve 68 disposed in the expansionchamber 62 and a retainer sleeve 69 disposed adjacent block 47 arerigidly attached to shaft 63 and serve to hold spacing block 60 to block47. Shaft 63 is rotatable through blocks 47 and 60 and is slidablewithin a hole 65. An Allen-head socket hole 70 is disposed in the end ofshaft 63 opposite the piston 64. A key 71 is attached to the piston andextends radially outward into'a' longitudinally extending keyway 72disposed in the block 60 and front case 16. By proper rotation of anAllen head wrench (not shown) in socket hole .70 in the end of shaft 63,shaft 63 may be rotated. Piston 64 will be restrained from rotating bykey 71 in keyway 72 and willbe caused to move along shaft 63 in adirection paral- -lel with longitudinal axis 15 in the expansion chamber62. As the piston moves along the shaft, the'volume of the expansionchamber varies accordingly. Notches 73may be scratched on keyway 72 toserve as a gauge to indicate the position of piston 64 on shaft 63.Chamber 62 is substantially airtight except for passage 74 which extendsradially from bore 14 through the barrel 13 and block 60 and intochamber 62 between piston 64 and sleeve 68. Aradial plate 75 is disposedin a plane perpendicular 'to longitudinal axis 15 and is attached aroundthe inside wall of front case 16 as by'welding. Plate 75 has a circularhole 76 of the same size as the outside diameter of barrel 13 to allowthe barrel to pass therethrough.

. Plate 75 is disposed from the end of front case. 16 opposite joint 18and adjacent piston 64 on the side opposite expansion chamber 62. Atubular sleeve 77 having an inside diameter greater than the outsidediameter of barrel 13 is attached concentrically around longitudinalaxis 15 to the plate 75 and extends toward the discharge end, 45

of barrel 13. V

e A tubular guard sleeve 80 has an outside diameter of substantially thesame size as the inside diameter of sleeve 77' and is adapted toslidetherein. A spring re-' straining plate 81 is attached around the innerperiphery of sleeve 80 at a distancefrorn an end 82 in a plane parallelto plate 75. Plate 81 has a circular hole 81a to envelope barrel 13 andslide thereon. spring 83 bears against plates 75 and 81 to provide aspacing between end 82 of sleeve 80 and plate 75. An

adapting ring 84 is attached to the end of sleeve 80 opposite end 82- asby welding. The inside peripheryof ring 84 slides against the outsideperiphery of barrel 13 adjacent the discharge end 45 and a safety guard85 is mounted on the outside periphery of ring 84. A nut 86 threadedonto the discharge end 45 of barrel '13 serves to attach the safetyguard 85 to sleeve 80. Nut 86 has a central opening 87 to allow the nail12 to pass from the barrel.

A compression A 1 Safety guard has a rectangular back 90 as shown in-F-IG; 8 with a flanged edge 91 around its periphery extending over nut86 to bear against the surface of the material to be fastened. Should itbe desired to drive a nail at a corner, which will obstruct the properposition of the guard, the safety guard may be shifted with respect tothe barrel 13 so that the barrel is disposed adjacent an end of theguard. The edge of the guard closest to the barrel is then placed intothe corner and the nail is driven. A pivot pin 92 inserted through theguard at an eccentrically located position from the center point on theback 90 as shown in FIG. 8. Pin 92 is attached to adapting ring 84 suchas bythreading it into a hole 93. g

A semicircular slot 94 having a Width equal to the outside diameter ofadapting ring 84 at the position where the guard is mounted to the ring,is disposed in back90 of guard 85 and extends therethrough. Slot 94'isdisposed concentrically around pin 92 and terminates with one Front case16 extends eccentrically around sleeve 77 to provide a muflier chambertherebetween longitu-j t dinally defined between plate 75 and the end101 of the front case. An exhaust port 102 extends through sleeve 77 asshown in FIG. 1 and a similar shaped port 103 1 extends through sleeve80. Barrel 13 has relief passages 104 disposed adjacent discharge end4510 allow gas: pressure generated by the explosive charge -to bedissipated from the bore after the nail has been actuated.

. Passages 104 allow the gas to escape into an intermediate" a chamber105 between barrel 13 and sleeve 80. When guard 85 is pressed against apiece of material, ports 102 I and 103 are aligned to-allow the gas topass into the 1. mufller chamber 100. By providing chambers 100 and 105,the sound emitted by the explosive charge will be baffied as it passesthrough the relief passages 104'andf ports 102 and 103. Additionalbaffling of the noise is provided by attaching a plate 106 perforatedwith holes.

107 on end 101 between front case 16 and sleeve 77. A latch arm 110shown in FIG. 2 is operable to hold spacing block 60 in a fixedlongitudinal position away from the handle when the guard is notattached to the barrel. In such a position, the barrel and firing pinblock' are also held stationary in a position away' from the handle.Since the sear mechanisrn 50 is fixed to the firing pin block'47 and thepawl 35 is attached to the handle 19, arm 39 of the pawl cannot engagewith lug 53 of sear 50 and the gun cannot be fired when latch arm 110 isin a latched position. The latch arm 110 is disposed in a longitudinalgroove in block 60 and has a hook 111 at one end engaged to block 60.Hook 111 is inserted into a hole 112 in the block and held therein byfrontcase 16. Latch arm 110 extends through a hole 113 in plate 75and'has a finger 114 at the end opposite the hook bearing on the innerWallof sleeve 77 when guard 85 and sleeve 80 areremoved. A latch tang-115 protrudes radially outward from latch arm'1-10 through a hole 116 infront case by a leaf spring 117. End 82 of sleeve 80 is flared to serveas a earn 118 so that finger 114 will be moved radially toward thebarrel 13, when sleeve 80 of the guard is inserted properly into sleeve77,'

thus causing latch tang to clear hole 116. Once thelatch tang isclear ofthe hole the spacing block and barrel.

assembly may be slid in the front; and rear case toward the "trigger tocock the firing pin.

A cartridge extractor lever 120 shown in FIGS. 2, 4,

and 5 is attached through a longitudinal slot 121 passing through frontcase 16 into spacing block 60 to a lug 122.v

Lug 122 is attached to one end of an extraction arm 123 which isdisposed longitudinally along the side of the device and terminated atan extraction element 124. A compression spring 125 disposed between aspring retainer 126 fixed to spacing block 60 and lug 122. Spring 125forces extraction arm 123 toward the discharge and of barrel 13 so thatthe end of extraction element 124 lies in a notch 127 in barrel 13 andis flush with breech end 44. Element 124 extends radially inward towardthe bore 14 and has a concave circular slot 128 in its end. Slot 128 hasthe same size diameter as bore 14 and is aligned to serve as a portionof the bore while element 124 is in notch 127. Element 124 has a groove129 in slot 128 of larger diameter than slot 128 to serve as part of thefiring chamber 56. Lever r110 is slidable in slot 111 to move element124 longitudinally away from barrel 13 to force cartridge 11 to bepulled out of bore 14 by head 1111.

A knockout pin 130 shown in FIGS. 1 and 6 is inserted into a hole 131 ina leg 132 on firing pin block 47 disposedadjacent trigger guard 24. Pin130 extends radially into slot28 andhas a head 133 which is forced by aspring 134 to bear against leg 132. By pushing pin 130 radially inwardagainst spring -134 to clear slot 28, the entire barrel assemblyincluding the firing pin block and front case may be removed from thehandle assembly and rear case.

FIG. 9 shows joint 18 with rear case 17 having a dog leg 135 of aconfiguration to engage snugly with front case 16. The irregularity atdog leg 135 of joint 18 shown in FIG. 9 continues around the peripheryof the cases to the limits 136 and 137 shown in FIG. 5. The front case16 may be pushed longitudinally away from the handle 19 to move theentire barrel assembly toward discharge end 44 until knockout pin 130strikes the end of slot 28 adjacent the trigger guard. At this position,dog leg 135 will be clear of the front case. It is desired that thelongitudinal distance which the front case must be moved is aboutone-eighth (Mr) inch to clear the dog leg. Firing pin block has anaccessary 138 so that shoulders 46 of barrel 13 will clear the firingpin block and the front case so that the front case, spacing sleeve, andbarrel may be rotated clockwise about shaft 63 as shown in FIG. 5. Whenthe front case is rotated from the rear case, easy access to the bore isprovided to load the gun with a nail 12 and a cartridge 11. The guard 85and sleeve 80 assembly are attached to bar-rel 13 by nut 86 so that thelatch tang 115 will clear hole 116 as previously described.

When the device is to be operated, the size of the expansion chamber 62must be adjusted in order to develop the required driving force. Thedriving force on the nail 12 can be adjusted in accordance with the typeof material into which the nail is to be driven. Some of the gasliberated from the explosion of the charge 11 will fiow into the chamberto consume some of the gas which would normally act upon the nail head.Decreasing the size of chamber 62 will increase the driving force on thenail because a smaller amount of gas will flow into the chamber and alarger amount of gas will force the nail to move longitudinally towardthe discharge end of the device. Similarly, increasing the size of thechamber will decrease the force on the nail. An Allen head wrench isinserted into socket 70 to rotate shaft 63. Rotating shaft 63 in aclockwise manner as shown in FIG. 5 will cause piston 64 to move towardthe handle and thereby decrease the size of the expansion chamber 62.Similar- 1y, rotating shaft 63 in a counterclockwise direction willincrease the size of the expansion chamber 62. Key 71 serves as anindicator to point to the gauge made by notches 73 in key-way 72 so thatthe operator may visually determine the proper setting of piston 64.

The front case 16 is pulled longitudinally away from the handle untilpin 130 strikes the end of slot 28 as previously described. The frontcase is then pivoted clockwise on shaft 63 to expose bore 14 and a nailsuch as nail 12'is inserted into the bore with the head 12a of the nailclosest to the handle. The explosive cartridge 11 having head 11a to fitinto groove 129 of firing chamber 56 is inserted into the bore such thatthe head is flush with breech end 44. The drawings show the nail head12a disposed between the passage 74 and the cartridge. Since passage 74is in the vicinity of the firing chamber 56, there is no differencewhich side of passage 74 the head of the nail is disposed. Once the nailhead passes. passage 74 the force on the head will be adjusted by theexpansion chamber. Once the nail and cartridge are inserted into thebore, the front case 16 is pivoted counterclockwise and then pushed backagainst the rear case so that dog leg 135 engages properly with thefront case. Firing pin 33 is disposed on axis 31 which is spaced fromaxis 15 so that pin 33 will strike cartridge 11 eccentrically .as shownin FIG. 2. The advantage to this eccentric spacing is that pin 33 willmiss the firing chamber and will not strike the cartridge until the dogleg 135 is properly engaged with the front case.

After the front and rear cases are connected at joint 18, a substantialspacing exists between end plate 2%! of the handle and resilient pad 48on firing pin block 47. Pin 33 will be in an uncocked position disposedtoward the discharge end of the gun. The pin will be restrained frommoving with the firing pin block 47 by the retaining sleeve 33a when thefront and rear case-s are pulled apart. The shaft 51 will move pastrearward section 3312 to the region of the front section of the pin 33where the shaft will be free to rotate to its counterclockwise positionby spring 52.

The guard is pressed against the material to be fastened, to forcesleeve 80 to slide into sleeve 77. Adapting ring 84 will slide on barrel13 until the end of nut 86 bears against the material. The barrelassembly including the spacing block and firing pin block will thenslide toward end plate 20 on the handle. As block 47 moves towards thehandle, shaft 51 of sear 50 will bear against section 33b of firing pin33 to move the pin into the chamber 30 and compress spring 32. Thefiring pin block 47 will move toward the end plate 20 until resilientpad 48 bears against the end plate causing the block to stop. When pad48 strikes plate 20 the sear 50 will be in an operable position withtrigger 23 shown in FIG. 7

and ports 102 and 103 will be aligned to allow gas to pass from chamber105 to chamber 100. The positional relationship between the scar and thetrigger is such that the trigger mechanism is ineffective until the pad48 bears against end plate 20. When the trigger is pulled arm 34 willstrike arm 37 of pawl 35 causing arm 39 to strike lug 53 of sear 50 androtate shaft 51 clockwise.

When shaft 51 is rotated clockwise the firing pin is released by flatland 55 and strikes the head 11a of cartridge 11 thereby causingdetonation.

The gas produced by detonation of the charge will force the nail 12toward the discharge end 45. After the head of the nail passespassageway 74 the gas enters into chamber 62 to relieve some of the gaspressure on nail head 12a. The nail continues to move along the bore bythe force from the gas pressure and after the head of the nail passesrelief passages 104 and the gas is discharged therethrough. The noise ofthe discharged gasses is attenuated by the chambers 1G5 and 100. Thenail will move into the material by its own inertia until the head 12astrikes the surface of the material.

After the nail is driven, the firing pin is in the uncocked positionwith the fiat land 5-5 bearing against rearward portion 33b of thefiring pin. The pressure of the gun on the material is released andcompression spring 83 forces the guard 85 and barrel assembly away fromthe handle. Front case 16 may then be manually pulled longitudinallyfrom the rear case as previously described and rotated clockwise aboutshaft 63. Cartridge ejector lever is pulled toward the handle whichcauses ejector element 124 to move longitudinally toward the 'handle toeject the used cartridge 11 from the bore by described. 7 I

This invention is not to be limited to the specific embodiment shown andillustrated herein, which is given byway of illustration rather than oflimitation; and the invention is not limited except by the scope of theap pended claims.

What is claimed is:

1. A cartridge powered gun for actua-ting a projectile, comprising abarrel having a bore disposed along alongitudinal axis and having abreech end and a discharge end, a spacing block embracing said barrel atsaid breech end and a firing pin block attached to said breech end, afiring chamber in gaseous communication with said bore to house saidcartridge, a firing pin passage disposed in said firing pin block andterminating at an edge of said firing chamber, a firing pin slidablyengaged in said firing pin passage to move toward said firing chamberfor a fixed distance, said cartridge disposed in the path of travel oisaid firing pin, said barrel and firing pin block being longitudinallyretractable to a retracted position from said firing pin such that saidfiring pin willterminate at the end of said fixed distance beforestriking said cartridge, a rotatable threaded pivot shaft extendingthrough said firing pin block and said spacing block in a directionparallel with said longitudinal axis,

said barrel being rotatable on said pivot shaft in a direction away fromsaid firing pin passage termination when. said barrel and firing pinblock are in said retracted posi-, tion; an expansion chamber in fluidcommunication with the barrel, and a piston threadedly engaged to .thepivot shaft and axially movable in said expansion chamber by turning thepivot shaft for varying the volume of said expansion chamber.

2. A cartridge powered gun in accordance with'claim 1 wherein saidbreech end has shoulders adapted to engage with an end ofsaid firing pinblock, an accessway disposed on said end of said firing pin blockadapted to release said shoulders as said barrel rotates away from saidtermination of said firing pin passage.

References Cited by the Examiner UNITED STATES PATENTS 2,679,645 6/ 1954Erickson et al. 144.5 12,700,764 2/1955 Catlin et al. 144.5

2,932,031 4/1960 Reymond 1-44.5, 3,009,157 11/1961 Kvavle 144.5 X r3,046,557 7/1962 Broughton et al. 1,-44.5. 1 3,050,732 8/ 1962 Termetl44.5 3,060,436 10/1962 De Caro et al. 144.5

FOREIGN PATENTS 810,686 3/1959 Great Britain.

GRANVILLE Y. OUSTER, JR., Prim ar -y Examier.

1. A CARTRIDGE POWERED GUN FOR ACTUATING A PROJECTILE, COMPRISING ABARREL HAVING A BORE DISPOSED ALONG A LONGITUDINAL AXIS AND HAVING ABREECH END AND A DISCHARGE END, A SPACING BLOCK EMBRACING SAID BARREL ATSAID BEECH END AND A FIRING PIN BLOCK ATTACHED TO SAID BREECH END, AFIRING CHAMBER IN GASEOUS COMMUNICATION WITH SAID BORE TO HOUSE SAIDCARTRIDGE, A FIRING PIN PASSAGE DISPOSED IN SAID FIRING PIN BLOCK ANDTERMINATING AT AN EDGE OF SAID FIRING CHAMBER, A FIRING PIN SLIDABLYENGAGED IN SAID FIRING PIN PASSAGE TO MOVE TOWARD SAID FIRING CHAMBERFOR A FIXED DISTANCE, SAID CARTRIDGE DISPOSED IN THE PATH OF TRAVEL OFSAID FIRING PIN, SAID BARREL AND FIRING PIN BLOCK BEING LONGITUDINALLYRETRACTABLE TO A RETRACTED POSITION FROM SAID FIRING PIN SUCH THAT SAIDFIRING PIN WILL TERMINATE AD THE END OF SAID FIXED DISTANCE BEFORESTRIKING SAID CARTRIDGE, A ROTATABLE THREADED PIVOT SHAFT EXTENDINGTHROUGH SAID FIRING PIN BLOCK AND SAID SPACING BLOCK IN A DIRECTIONPARALLEL WITH SAID LONGITUDINAL AXIS, SAID BARREL BEING ROTATABLE ONSAID PIVOT SHAFT IN A DIRECTION AWAY FROM SAID FIRING PIN PASSAGETERMINATION WHEN SAID BARREL AND FIRING PIN BLOCK ARE IN SAID RETRACTEDPOSITION; AN EXPANSION CHAMBER IN FLUID COMMUNICATION WITH THE BARREL,AND A PISTON THREADEDLY ENGAGED TO THE PIVOT SHAFT AND AXIALLY MOVABLEIN SAID EXPANSION CHAMBER BY TURNING THE PIVOT SHAFT FOR VARYING THEVOLUME OF SAID EXPANSION CHAMBER.